x2=-7x+9

Solution for x2=-7x+9 equation:

x2=-7x+9

We move all terms to the left:

x2-(-7x+9)=0

We add all the numbers together, and all the variables

x^2-(-7x+9)=0

We get rid of parentheses

x^2+7x-9=0

a = 1; b = 7; c = -9;
Δ = b2-4ac
Δ = 72-4·1·(-9)
Δ = 85
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(7)-\sqrt{85}}{2*1}=\frac{-7-\sqrt{85}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(7)+\sqrt{85}}{2*1}=\frac{-7+\sqrt{85}}{2}
$